This application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C. xc2xa7119 from my application DISCHARGE MUFFLER OF A HERMETIC ROTARY COMPRESSOR filed with the Korean Industrial Property Office on Jan. 14, 1999 and there duly assigned Serial No. 754/1999.
1. Field of the Invention
The present invention relates to a hermetic rotary compressor which constitutes a refrigerating cycle of an air conditioner, a refrigerator, or the like, and more particularly to a discharge muffler for reducing noises which occur due to pulsation of refrigerant and impact to a valve when the refrigerant, which is compressed in a cylinder, is discharged.
2. Description of the Prior Art
Generally, a hermetic compressor comprises a compression unit, and a motor for driving the compression unit, which are installed within a sealed casing. Such a hermetic compressor is usually classified according to the operation type of compression unit, into a reciprocating type compressor, a scroll type compressor, and a rotary type compressor.
Among these, FIG. 1 shows a rotary type compressor which has a relatively superb performance in comparison with its simple structure.
FIG. 1 is a vertical sectional view of a conventional hermetic rotary compressor, in which the reference numeral 10 refers to a sealed casing, 20 refers to a motor, and 30 refers to a compression unit.
As shown in FIG. 1, the compression unit 30 comprises a pair of flanges 32 and 34 for supporting an eccentric shaft 22 of the motor, a cylinder 36 which is disposed between the flanges 32 and 34, and a roller 38 which surrounds the eccentric shaft 22.
The refrigerant which is sucked into an inner space defined by the cylinder 36 through a suction port 52, is compressed by the rotational movement of the roller 38. The compressed 25 refrigerant is discharged into an inner space of the sealed casing 10 through a discharge port 33 which is formed on the upper flange 32.
The reference numeral 40 in FIG. 1 refers to a discharge muffler. The discharge muffler 40 functions to reduce the noise which occurs due to the pulsation of the refrigerant and the noise which occurs due to the impact to a valve 39 when the refrigerant is discharged through the discharge port 33. Such the discharge muffler 40 is in such a shape that is shown in FIGS. 2 and 3, and is disposed above the upper flange 32 to define a noise reducing space with the upper flange 32, so that the noise reducing space is defined between the discharge muffler 40 and the upper flange 32. Accordingly, the refrigerant is discharged through the discharge port 33 to the noise reducing space, and then discharged into the inner space of the sealed casing 10 through a pair of discharge openings 42 which are formed on the discharge muffler 40. In such a situation, the noise, which is produced while the refrigerant is discharged, is reduced while the refrigerant is expanded in the discharge muffler 40. As described, the purpose of employing the discharge muffler 40 is to reduce the noise. In FIG. 1, the reference numeral 60 refers to an accumulator.
In the conventional discharge muffler, however, since the refrigerant, which is discharged into the noise reducing space, is directly discharged through the discharge openings, the noise from the pulsation of refrigerant and the impact to the valve are not reduced, satisfactorily.
Further, in the conventional hermetic rotary compressor, since the oil for lubricating the eccentric shaft 22 is discharged together with the refrigerant when the refrigerant is discharged through the discharge port 33, and since there is no separate device for suppressing the amount of discharged oil, the amount of discharged oil increases while the amount of discharged refrigerant decreases. Accordingly, the efficiency of the compressor is deteriorated.
A Japanese Patent Laid-Open No. 2-61375 discloses a noise reducing device of a hermetic compressor, which overcomes the above-described problems of the prior art, and is shown in FIGS. 4 and 5.
As shown in FIGS. 4 and 5, the noise reducing device of the hermetic compressor has a connecting pipe 44xe2x80x2 which is disposed at a lower side of the discharge opening 42xe2x80x2 of the discharge muffler 40xe2x80x2. The connecting pipe 44xe2x80x2 serves as a resonance device to reduce the noise. The hermetic compressor, however, has a disadvantage in that the structure and manufacturing process thereof are complex.
The present invention has been developed to overcome the above-mentioned problem of the prior art, and accordingly, it is an object of the present invention to provide a discharge muffler of a hermetic rotary compressor which has a simple structure and reduces the noises which occur due to the pulsation of the refrigerant and the impact to the valve when the refrigerant is discharged.
The above object will be accomplished by the discharge muffler according to the present invention which comprises a muffler body, and a phase varying means. The muffler body is disposed above an upper flange having a refrigerant discharge port to define a noise reducing space with the upper flange. The muffler body has a pair of discharge openings. The phase varying means blocks the noises which occur due to the pulsation of the refrigerant and the impact to a valve when the refrigerant is discharged. Here, the valve is disposed at a discharge port. The phase varying means prevent the noises which occurs due to the pulsation of the refrigerant and the impact to the valve, from being discharged together with the refrigerant. The phase varying means also counterbalances the noises by varying the phases of the noises.
The phase varying means comprises a pair of covers which extend from the muffler body toward the center of the discharge opening. The covers cover approximately half portion of the discharge opening from above and from below, respectively, in an alternating pattern.
Here, the phase varying means is formed at a pair of discharge openings, respectively, and has such an arrangement that permits the refrigerant to be discharged in the circumferential direction of the muffler body.
Further, a pair of covers can be designed either in a hemispheric shape, or in a semi-oval shape, or in any shape only if it is of spheric shape.
Accordingly, the noise which is produced while the refrigerant is discharged, is blocked by the phase varying means, and simultaneously, the phases of the noises are varied so that the noises are counterbalanced. As a result, the great noise reduction effect is guaranteed with a simple structure.